Aspyr has posted a demo of Homeworld 2. Homeworld 2 is a Sci-Fi 3D real-time strategy game that puts you in the command of large fleets of space ships. The game offers place to research their own new technologies, and to use those technologies in the development of new fleets.
Aspyr notes that the full game has both a single player and multiplayer component, as well as features like the ability to zoom in to get close ups of your ships, and more.
The Homeworld 2 demo is a free download, and the full retail version is priced at US$49.99 (Amazon). You can find more information on the game at Aspyris Web site, including links to trailers and other resources.